Field of the Invention
The present invention relates to a mask and a mask assembly, and more particularly, to a mask and a mask assembly used to deposit an organic layer.
Description of the Related Art
In general, representative examples of a flat panel display include an organic light emitting display, a liquid crystal display, and a plasma display panel.
Among them, an electrode and an organic light emitting layer having specific patterns need to be formed in order to manufacture the organic light emitting display, and a deposition method using a mask assembly may be adopted as a method for forming the electrode and the organic light emitting layer.
More particularly, the organic light emitting display has a configuration in which pixels, which are basic units of image representation, are arrayed on a substrate in a matrix pattern, and an organic light emitting element, in which a positive first electrode and a negative second electrode are sequentially laminated with respective organic light emitting layers that emit beams of red, green, blue, white, and the like in respective pixels, is disposed. Herein, an organic material configuring the organic light emitting layer is very weak with respect to moisture and oxygen, and as a result, the organic light emitting layer needs to be completely isolated from moisture during a process of forming the organic light emitting layer and even after forming the organic light emitting layer. Therefore, it is difficult to perform patterning by using a general photolithography process. Accordingly, the organic light emitting layer, or the like, is primarily formed only in a part corresponding to each pattern by using a mask with an active pattern, through which a deposition material penetrates.
In recent years, a mask assembly is used, which includes a frame having an opening, and a plurality of masks having a band shape in which opposite ends are fixed to the frame so as to correspond to the opening.
Since tensile force is applied to the mask assembly of the related art, which is supported on the frame, a form of the active pattern formed in the mask deteriorates as a result of the tensile force applied to the mask.
The above information disclosed in this Background section is only for enhancement of an understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.